Severable carton wall

ABSTRACT

A frangible line defines a line of severance by extending across a carton wall that has a seam. The frangible line is extensively weakened along a predetermined segment where it traverses the seam. Preferably, the predetermined segment is extensively weakened by substantially disjoining the panel regions on either side of the line. Disjoinder is preferably achieved by making the predetermined segment a cut line.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] (Not Applicable.)

STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT

[0002] (Not applicable)

TECHNICAL FIELD OF THE INVENTION

[0003] The invention relates to cartons, and more particularly tocartons having a wall severable along a frangible line of severancewherein the line of severance traverses a joinder of panels.

BACKGROUND OF THE INVENTION

[0004] Cartons made of flexible material, such as paperboard, are oftenused in a manner that requires that one of the carton walls be partiallyor fully severed to gain partial or full access to the interior of thecarton. Sometimes access is for the purpose of removing or depositingarticles such as beverage cans or bottles. Typically, the carton isseverable along a frangible region or line such as a perforated line ortear strip. An example of a carton wherein at least a portion of thecarton wall is severable is U.S. Pat. No. 5,518,111.

[0005] In order to be effective for the packaging of articles, a cartontypically must be constructed in some type of arrangement wherein apartially or fully enclosed structure is formed. For example, aquadrilateral-shaped tubular structure such as the carton of U.S. Pat.No. 5,518,111. Cartons are typically erected from flat sheets known asblanks. To form such a closed carton structure, it is typicallynecessary to join certain regions of the blank in some fashion. The endsof carton panels are typically joined by adherence such as gluing. Aseam is generally formed where the panel ends overlap.

[0006] Often, it maybe desirable to sever a carton wall across a joinderof panels. It is generally more difficult to tear across a carton seamthan an un-joined carton wall. The seam is essentially a reinforcedregion because it is multiple-ply and any adhesive used typically addsits own resistance to shearing. A carton wall may de-laminate, that is,come apart in layers, or otherwise have portions that give way in anundesirable manner due to the resistance to shearing presented by aseam. Thus, it can be appreciated that it would be useful to have ameans for severing a carton wall across a seam.

BRIEF SUMMARY OF THE INVENTION

[0007] In accordance with a preferred embodiment of the invention, afrangible line defines a line of severance by extending across a cartonwall that has a seam. The frangible line is extensively weakened along apredetermined segment where it traverses the seam. Preferably, thepredetermined segment is extensively weakened by substantiallydisjoining the panel regions on either side of the line. Disjoinder ispreferably achieved by making the predetermined segment a cut line.

[0008] In accordance with another aspect of the preferred embodiment ofthe invention, the predetermined extensively weakened segment isarcuate.

[0009] In accordance with another aspect of a preferred embodiment ofthe invention, in the portion of each panel that overlaps to form theseam, the frangible line terminates in an arcuate extensively-weakenedsegment. The arcuate segments are disposed to substantially align withone another when the seam is formed.

[0010] In accordance with a further embodiment of the invention, thearcuate segments are at least slightly offset from one another when theseam is formed.

[0011] In accordance with still another embodiment of the invention, theterminal end of an extensively weakened line segment of a panel isfrangibly joined to the panel adjacent the edge of the panel. Preferablyjoining is by means of a nick member.

[0012] Other advantages and objects of the present invention will beapparent from the following description, the accompanying drawings, andthe appended claims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0013] Exemplary embodiments of the invention will now be described byway of example only, with reference to accompanying drawings in which:

[0014]FIG. 1 is a perspective illustration of a carton having aseverable wall in accordance with a preferred embodiment of theinvention;

[0015]FIG. 2 is a perspective view of the carton of FIG. 1 wherein atrough that is hinged to the carton along a frangible line also servingas a severance line has been flipped down;

[0016]FIG. 3 is a perspective view of the trough of FIG. 2 in removedcondition with respect to the remainder of the carton;

[0017]FIG. 4 is an elevational view of the trough of FIG. 3;

[0018]FIG. 5 is a plan of a blank for forming the carton of FIG. 1; and

[0019]FIG. 6 is an enlarged plan view of a portion of the blank of FIG.5.

DETAILED DESCRIPTION OF THE INVENTION

[0020] Throughout the drawings, the same reference numerals are used todenote the same or like features of the invention.

[0021] Referring first to FIG. 1, therein is illustrated a carton 10having a severable carton wall in accordance with the teachings of thepresent invention. For purposes of describing the invention, anelongated tubular carton 10 is illustrated. However, the teachings ofthe invention are not limited to any particular carton shape orconfiguration.

[0022] The carton 10 has an end region that terminates in a compositewall formed from panels that overlap along a seam 58. The seam 58 is theoverlapping portion between panel edges 54 and 56. In the illustrationsof the erected carton, one panel edge 54 or 56 will be shown as hiddenthrough use of a dotted line. For convenience of understanding thecarton 10 structure will first be discussed. For this purpose, referenceis now made simultaneously to FIG. 1 and FIG. 5. FIG. 5 is anillustration of a blank 12 for forming the carton of FIG. 1. The blank12 is shown from its inner surface. That is, the carton 10 is formed byfolding the blank 12 outwardly from the plane in which the illustrationlies.

[0023] Using the disposition of the carton in FIG. 1 as a point ofreference, a top panel, side panels 22, 26, and bottom wall panels 24,28 are interconnected and form the basic tubular structure of theerected carton 10. A handle 21 is formed in the top panel 20. Endstructures of the carton are formed from what are typically referred toin the carton field as major and minor flaps.

[0024] The terms “flap” and “panel” will be used interchangeably in thisdiscussion. Minor flaps 34, 36, 38 provide innermost closure for the endof the carton 10. For convenience and ease of understanding, the majorflaps are described as left and right upper and lower portions. Theseorientations have been used as an aid in describing the invention andnot as limitations upon its teachings. The right major flap (as viewedfrom a point of orientation facing the page illustrating the erectedcarton) has lower 40 and upper 50 portions. Likewise, the left majorflap has lower 42 and upper 52 portions. Closure of the ends of thecarton is accomplished by securing the end regions of the major flaps40/50, 42/52 to one another in overlapping condition. The overlap of theend regions creates a seam 58 (as briefly mentioned above) definedbetween the edges 54, 56 of the major flaps.

[0025] A frangible line 60, 62 extends across each major panel 40/50,42/52 and, in the carton illustrated, into other portions of the carton.The full extension of the frangible line defines a trough 100 that isseparable from the carton 10. The trough 100 will be discussed later inthis description. The frangible line 60, 62 is used as a reference pointfor denoting the lower 40, 42 and upper 50, 52 portions of the majorflaps.

[0026] The frangible line 60, 62 may be any weakened line thatfacilitates separation of the panel portions lying on either side of theline. The invention contemplates frangible lines to include but not belimited to perforated lines, tear strips, fold lines and cut linesintermittently joined by nick members. In the carton-making field a“nick member” is generally considered to be an interconnecting sliver(or similar extremely small portion) of material bridging disjoinedportions of material.

[0027] The frangible line that extends across the end wall of the cartonresults from the coincidence of the frangible line 60, 62 that extendsacross each major end flap 40/50, 42/52. Each frangible line segmentthat extends across the major flaps terminates at an edge 54, 56 of eachmajor flap 40/50, 42/52. Each segment of the frangible line that extendsacross the seam (that is, the overlapping or overlapable portion of themajor flap) is extensively weakened. That is, is more weakened than theother portion of the frangible line to enable even greater ease ofseparation. The extensively-weakened segments 70, 72 lie adjacent theedges of the major flaps. Extensive weakening may be accomplished by adeeper score or a more severely interrupted perforated line. In oneaspect of the preferred embodiment of the invention, extensive weakeningis accomplished by creating a cut line.

[0028] In a further aspect of the preferred embodiment, eachextensively-weakened line segment 70, 72 includes a nick member 80, 82near the line segment's 70, 72 intersection with the flap edge 54, 56,particularly when a cut line is used. The nick member helps stabilizethe edge region of the flap during erection of the blank 12 into acarton 10.

[0029] The frangible line 60, 62 creates a line along which portions ofthe carton wall that lie on either side of the line may be severed fromone another. The frangible line also creates a hinge about which theopposing panel portions may be pivoted with respect to one another.Reference now may also be made to FIG. 2 wherein the frangible lineserves as a hinge 64 between lower 40, 42 and upper 50, 52 major flapportions. The hinged portions may thereafter also be separated from oneanother by tearing along the hinge/frangible line. Theextensively-weakened line segment 70, 72 of the frangible line helpslessen or eliminate the impact of the reinforced carton region resultingfrom the seam 58. Along the extensively-weakened segments 70, 72 thereis no carton material that will inhibit tearing or bending. At most,only an adhesive such as glue that may be used in joining the flaps willbe present.

[0030] In accordance with another aspect of a preferred embodiment ofthe invention, the extensively-weakened line segments 70, 72 arearcuate. The arcuate line segment configuration facilitates greater easeof clean separation of panel portions and lessens the tendency of thepanels to de-laminate at the seam 58. The curvature of the arcuatesegments produces an offset between the line where tearing or shearingstresses are being primarily applied and the region of the seam 58 wherestresses are applied. In the case where the lower and upper portions ofthe end wall are pivoted out of a single plane along the hinge formed bythe frangible line, as illustrated in FIG. 2, the offset created by thecurvature causes opposing panel portions to completely sever from oneanother on either side of the extensively-weakened, or cut, line. Thus,there is no connection of wall or panel portions across the seam 58 atthis juncture. Once the seam has been eliminated, tearing along thefrangible line is easily accomplished. The curvature of the arcuate linesegments also results in the creation of protrusions 90, 92 on one sideof the line segments and notches on the opposing side. The protrusionsare reinforced because of the panel overlap. Thus, as can be seen inFIG. 2, an upright member is created in the erected carton that helpsfacilitate separation of the wall/panel portions along the seam 58.

[0031] The line segments are disposed for substantial alignment withrespect to one another when the edge regions of the major flaps areoverlapped and joined to one another. Although the invention teachessubstantial alignment of the lien segments 70, 72, in accordance withanother aspect of the preferred embodiment, this alignment alsocontemplates a slight offset between arcuate segments. This offset isaccomplished when one arcuate segment 72 has a curvature greater thanthe other arcuate segment 70. The difference in degree of curvature ofthe line segments 70, 72 can be more clearly seen in the enlarged viewof a portion of the blank 12 illustrated in FIG. 6 and in the troughillustrations of FIGS. 3 and 4 (which will be described in greaterdetail below). The resulting difference in size of protrusions 90, 92can be seen in the exaggerated depiction of these features in FIG. 2.When the arcuate segments and protrusions are offset, the lower andupper wall portions may be more easily separated, particularly whenpivoted, because clearance between the protrusion and notch is providedfor. In the preferred embodiment, the arcuate segment 72 that lieswithin the inner ply of the seam 58 in flap 52 is made larger than thearcuate segment 70 that lies in the outer ply in flap 50 to provide thenecessary clearance.

[0032] The invention is particularly useful in providing a hinge 64 thatcan subsequently serve as a line of severance for a trough 100 formed atthe end of a carton 10. FIGS. 1 and 2 show the manner in which afrangible line inscribes a trough that can be pivoted downward to serveas a receptacle for articles such as cans 5. The pivoted trough can beremoved by tearing along the hinge/severance line without resistancefrom the seam 58. The removed trough is shown in FIGS. 3 and 4. Theseviews also illustrate the offset of the arcuate lien segments 70, 72discussed above.

[0033] The invention provides a means for reliably severing a cartonpanel across a seam while maintaining the integrity of the cartonformation process. The invention essentially offsets a region ofreinforcement (created by the seam) from the line of severance (afrangible line). Because of the teachings of the invention, severance ofa carton wall at a predetermined region is attainable in a carton thathas been formed in a typical manner with seams disposed as appropriatefor its function. The invention enables a severance mechanism to beutilised without being limited by the disposition of a carton seam. Asillustrated above, the invention is particularly useful in the casewhere the line of severance serves as a hinge prior to severance. Inthis manner, the reinforced seam is even further isolated from the lineof severance.

[0034] Use of terms such as top, bottom, side, end, longitudinal andtransverse are used for convenience and to provide a point of referencein the description of the preferred embodiment of the invention and arenot meant to limit the scope of the invention. Modifications may be madein the foregoing without departing from the scope and spirit of theclaimed invention.

1. A severable carton wall comprising: a composite wall formed frompanels joined along a seam; and a frangible line extending across thecomposite wall, traversing the seam, defining a line of severance;wherein a segment of the frangible line that traverses the seam isextensively weakened.
 2. The invention of claim 1, wherein theextensively-weakened segment of the line that traverses the seam is acut Line.
 3. The invention of claim 1, wherein the extensively-weakenedsegment of the line that traverses the seam is arcuate.
 4. The inventionof claim 3, wherein the arcuate extensively-weakened line segment isformed by terminal arcuate line segments defined adjacent respective endedges of panels that overlap to form the seam.
 5. The invention of claim4, wherein the terminal arcuate line segments are substantially alignedwith respect to one another.
 6. The invention of claim 4, wherein theterminal arcuate line segments are at least slightly offset from oneanother.
 7. The invention of claim 6, wherein the terminal arcuate linesegment in the panel that is disposed outermost with respect to the seamhas a first radius at least slightly smaller than a second radius of theterminal arcuate line segment of the innermost panel.
 8. The inventionof claim 4, wherein regions of the panel disposed on either side of eachterminal arcuate line segment are releasably joined proximate the edgeof the panel.
 9. The invention of claim 8, wherein the regions of thepanel are releasably joined by at least one nick member.
 10. A removablecarton trough comprising: a substantially tubular carton having at leastone end region terminating in a composite end wall having a seam; and aseparable trough formed from a portion of the end region hingably andseverably connected to the end wall along a frangible line thattraverses the seam; wherein a segment of the frangible line thattraverses the seam is extensively weakened.
 11. The invention of claim10, wherein the extensively-weakened segment of the line that traversesthe seam is a cut line.
 12. The invention of claim 10, wherein theextensively-weakened segment of the line that traverses the seam isarcuate.
 13. The invention of claim 12, wherein the arcuateextensively-weakened line segment is formed by terminal arcuate linesegments defined adjacent respective end edges of panels that overlap toform the seam.
 14. The invention of claim 13, wherein the terminalarcuate line segments are substantially aligned with respect to oneanother.
 15. The invention of claim 13, wherein the terminal arcuateline segments are at least slightly offset from one another.
 16. Theinvention of claim 15, wherein the terminal arcuate line segment in thepanel that is disposed outermost with respect to the seam has a firstradius at least slightly smaller than a second radius of the terminalarcuate line segment of the innermost panel.
 17. The invention of claim13, wherein regions of the panel disposed on either side of eachterminal arcuate line segment are releasably joined proximate the edgeof the panel.
 18. The invention of claim 17, wherein the regions of thepanel are releasably joined by at least one nick member.
 19. A blank forforming an erected carton having a severable carton wall, the blankcomprising: a plurality of panels for forming a composite wall joinedalong a seam in the erected carton; and a frangible line extendingacross the panels disposed for defining a line of severance traversingthe seam; wherein a segment of the frangible line that is disposed fortraversing the seam is extensively weakened.
 20. The invention of claim19, wherein the extensively-weakened segment of the line that isdisposed for traversing the seam is a cut line.
 21. The invention ofclaim 19, wherein the extensively-weakened segment of the line that isdisposed for traversing the seam is arcuate.
 22. The invention of claim21, wherein the arcuate extensively-weakened line segment is formed byterminal arcuate line segments defined adjacent respective end edges ofones of the panels that overlap to form the seam.
 23. The invention ofclaim 22, wherein the terminal arcuate line segments are disposed forsubstantial alignment with respect to one another in the erected carton.24. The invention of claim 22, wherein the terminal arcuate linesegments are disposed to be at least slightly offset from one another inthe erected carton.
 25. The invention of claim 24, wherein the terminalarcuate line segment in one of the panels that will be outermost withrespect to the seam in the erected carton has a first radius at leastslightly smaller than a second radius of the terminal arcuate linesegment of the other of the panels that will be innermost in the erectedcarton.
 26. The invention of claim 22, wherein regions of ones of thepanels disposed on either side of each terminal arcuate line segment arereleasably joined proximate the edge of the respective panels.
 27. Theinvention of claim 26, wherein the regions of the panels are releasablyjoined by at least one nick member.
 28. A blank for forming a cartonhaving a removable carton trough, the blank comprising: a plurality ofpanels for forming a substantially tubular carton defining at least oneend region terminating in a composite end wall having a seam; and forforming a separable trough from a portion of the end region hingably andseverably connected to the end wall along a frangible line that isdisposed for traversing the seam; wherein a segment of the frangibleline that traverses the seam is extensively weakened.
 29. The inventionof claim 28, wherein the extensively-weakened segment of the line thatis disposed for traversing the seam is a cut line.
 30. The invention ofclaim 28, wherein the extensively-weakened segment of the line that isdisposed for traversing the seam is arcuate.
 31. The invention of claim30, wherein the arcuate extensively-weakened line segment is formed byterminal arcuate line segments defined adjacent respective end edges ofpanels that overlap to form the seam.
 32. The invention of claim 31,wherein the terminal arcuate line segments are disposed for substantialalignment with respect to one another in the erected carton.
 33. Theinvention of claim 31, wherein the terminal arcuate line segments aredisposed to be at least slightly offset from one another in the erectedcarton.
 34. The invention of claim 33, wherein the terminal arcuate linesegment in one of the panels that will be outermost with respect to theseam in the erected carton has a first radius at least slightly smallerthan a second radius of the terminal arcuate line segment of the otherof the panels that will be outermost in the erected carton
 35. Theinvention of claim 31, wherein regions of ones of the panels disposed oneither side of each terminal arcuate line segment are releasably joinedproximate the edge of the respective panels.
 36. The invention of claim35, wherein the regions of the panels are releasably joined by at leastone nick member.